Bill de Blasio, with his "Tale of Two Cities" message, and Bill Thompson, who was always the guy to beat, took their battle for the Democratic nomination for mayor into the heart of Harlem on Thursday.

To understand why de Blasio has surged to the front of the pack — past those fleeting flavors of the month like Christine Quinn and Anthony Weiner — you needed to watch him in action at W. 125th St. and Lenox Ave.

Advertisement

He is a candidate who doesn't simply stretch out his hand, ask complete strangers for their vote and quickly move on.

Instead, he listened intently as 51-year-old Rudolph Spivey, a Harlem resident all his life, spent nearly five minutes pouring out his troubles.

Spivey said he'd worked for years at a city job, training the unemployed for new careers, until he got laid off himself back in 2010. He hasn't been able to find work since then.

The candidate quietly told him what he'd do as mayor to help the unemployed.

"I like what I'm hearing," Spivey said. "After all these years of Bloomberg, who doesn't understand the working man, we need de Blasio."

And so it was with each person who walked up to the candidate.

Dina Doyer, near tears, explained how the Mitchell-Lama building she'd lived in for decades on a Section 8 housing subsidy had been sold to a developer, and the new owner wanted to sell off the apartments.

De Blasio assured her he'd fight to keep housing affordable and strengthen rent regulations, and he pulled out a card with the name of an assistant for her to contact.

More than the other contenders, de Blasio understood most New Yorkers have not fully recovered from the Great Recession of 2008, that many resent this "Tale of Two Cities" we have become.

Harlem, for example, is booming with luxury housing, while longtime residents are pushed out every day.

De Blasio turned that understanding into a consistent narrative: After 12 years of Bloomberg, who catered first and foremost to landlords, Wall Street moguls and charter school promoters, who allowed the police to turn stop-and-frisk into a massive abuse of the city's black and brown residents, it's time for a change.

By all rights, Thompson should have been the front-runner. After all, he is the most likable and experienced of the candidates.

He ran a strong campaign against Bloomberg four years ago and has the backing not only of many influential black and Hispanic leaders but of some business leaders and law enforcement unions.

And Thompson might still force a runoff with de Blasio next week, judging by the enthusiastic support he received campaigning in Harlem on Thursday.

Advertisement

But when it comes to stop-and-frisk, a pivotal issue in the black community, Thompson played it safe. He spoke out against the misuse of the practice, but then opposed legislation in the City Council backed by key black leaders like Brooklyn Councilman Jumaane Williams and the Rev. Al Sharpton.

De Blasio also supported the measures.

"I've disagreed with Bill Thompson's view that stop-and-frisk can be fixed," Sharpton said.

So despite being a friend of Thompson's for more than 30 years, Sharpton is staying neutral in Tuesday's vote — a likelihood he first raised to the Daily News back in June.

As with stop-and-frisk, so too with unemployment, affordable housing and education.

The more this theme of two cities resonates with voters, the more support for de Blasio surges.